The preparation of aqueous solutions of silver dihydrogen citrate (SDC) and citric acid was described in U.S. Pat. No. 6,197,814, incorporated herein by reference. In this method, the SDC is generated electrolytically in a solution of 5-25% citric acid. According to the '814 patent, the resulting aqueous disinfectant may optionally be mixed with alcohol and/or a detergent and can be used on exposed or contaminated surfaces to kill bacteria, virus, fungi and other microorganisms. It can also be used to disinfect wounds and to behave as a disinfectant in water systems, such as cooling towers, hot water systems, potable water systems, etc.
PCT publication WO2005/041861 and U.S. Pat. No. 7,732,486, also incorporated herein by reference, describes preparing an anhydrous form of the SDC/citric acid solution for ease of transport. According to this publication, in order to employ the anhydrous form as a disinfectant, it should be reconstituted to recreate the aqueous systems described in the '814 patent. As noted in the '861 publication and the '486 patent, the anhydrous form is capable of being reconstituted to a fully-active aqueous disinfectant.
It has now been found that reconstitution of this anhydrous form is unnecessary, and that the anhydrous form itself may be employed in non-aqueous systems as an in situ disinfectant and antimicrobial protectant.